1. Technical Field
The present invention relates to a dryer-ironer wherein the laundry is ironed between a heated ironing cup and a rotating roller.
The dryer-ironer according to the invention may be used in all cases where relatively large amounts of laundry must be frequently ironed. Thus and uniquely as an example, such a machine may be used in hospital institutions, nursing homes, lodging houses, hotels, restaurants, etc.
2. State of the Art
In dryers-ironers with a cup, ironing of the laundry is performed between a metal ironing cup, in the shape of a cylindrical sector with a generally horizontal axis, and a pressing roller covered with baize, the axis of which coincides with that of the cup and the lower portion of which rests on said cup. When the machine is operating, the pressing roller is driven into rotation around its axis. Consequently, the pieces of laundry to be ironed, inserted between the cup and the roller on one side of the machine, come out on the other side.
For ironing of laundry to be carried out in the best possible conditions, the ironing cup is provided with heating means. Depending on the machines, these heating means may either be totally integrated into the machine, or else placed outside the latter.
When the heating means of the ironing cup are integrated into the dryer-ironer, they may be of different types, depending on the machines. Hence, these heating means may notably consist of gas manifolds, electric resistances, infrared heating devices, etc.
Machines of this type provide the advantage of being simple and not very expensive and of having excellent cost effectiveness.
On the other hand, they have the drawback that the cup is uniformly heated on its entire length, regardless of the areas where the pieces of laundry are inserted during ironing. Consequently, after ironing a piece of laundry in a given area of the ironing cup, this area is at a lower temperature than the value required for the ironing, whereas the other areas of the cup, which continue to be heated, are on the contrary at a higher temperature than this value. Consequently, the next piece of laundry will be badly ironed if it is inserted in the same area as the previous one or be burnt if it is inserted in a different area. Actually, the thermal gradient even increases if several pieces of laundry are successively inserted substantially in the same area.
Dryers-ironers wherein the ironing cup is heated by means located outside the machine, use a heat carrying fluid. This heat carrying fluid is heated in a boiler located outside the machine, before being fed into the cup by a pump also placed outside the machine.
Contrary to dryers-ironers wherein the heating means of the cup are integrated into the machine, dryers-ironers with a heat carrying fluid are able to provide good heat diffusion on the entire length of the cup, regardless of the areas into which are inserted the pieces of laundry.
On the other hand, these machines have the drawbacks of requiring heavy, expensive and complex external facilities.
When several dryers-ironers are placed in a same building, these drawbacks sometimes result in that the users feed these machines with heat carrying fluid simultaneously, from a unique circuit integrating a single boiler and a single pump. However, such facilities are only feasible if several dryers-ironers are used simultaneously and they remain more expensive and more complex than facilities using machines with integrated heating.
Specifically, the object of the invention is a dryer-ironer with heated cup, its original design allows it to benefit both from cost effectiveness and cost advantages specific to machines with integrated heating and from the advantages provided by uniform diffusion of heat on the entire length of the cup of machines which are heated through a heat carrying fluid.
According to the invention, this result is obtained by means of a dryer-ironer comprising an ironing cup in the shape of a cylindrical sector provided with an internal wall, able to come into contact with the laundry to be ironed, and means for heating said wall, characterized in that the cup further comprises an external wall which externally lines, at a distance, the internal wall, directly close to the heating means, so as to delimit with said internal wall, a closed chamber filled with a heat carrying fluid able to transfer heat produced by heating means to the internal wall, and stirring means able to generate a circulation of heat carrying fluid within said chamber.
The machine according to the invention has integrated heating means. It thus benefits from economical advantages and from the excellent cost effectiveness both specific to this type of machine.
On the other hand, the use of a heat carrying fluid put into circulation by stirring means also integrated into the machine, provides effective diffusion of heat over the entire length of the ironing cup, as in machines using an external boiler.
In a preferred embodiment of the invention, the stirring means comprise partitions positioned in a staggered configuration within the closed chamber, in order to delimit between the internal and external walls, a path for reciprocating motion, substantially parallel to an axis of the cylindrical sector formed by the cup. The stirring means also comprise driving means such as a pump in order to cause the heat carrying fluid to circulate along this path.
The heating means, which may assume any shape as in existing machines with integrated heating, are advantageously placed outside the closed chamber.
Moreover, the internal wall of the cup is advantageously made of stainless steel and the external wall of ordinary steel.